Abstract: Based on the limit equilibrium method, stability analyses of the reinforced multi-tiered wall are conducted to calculate the required strength of geosynthetics. The available reinforcement tensile capacity against the front and rear-end pullout is used to determine the distribution of the required strength and the strength of connection to the facing for each layer. The calculated solutions are compared with the results obtained from the experiments or numerical simulations for the verification of the presented method. A series of parametric study is carried out to investigate their influences on the stability of reinforced multi-tiered wall and its critical failure surface. Several conclusions are drawn from the results. Compared with the calculated results of this study, the active earth pressure theory recommended by FHWA could conservatively estimate the stability of the multi-tiered wall. The composite failures due to the insufficient reinforcement length can be avoided by increasing offset distance and number of tiers. The connection strength can suddenly increase at the step and then the bottom facing block should be embedded at a deep depth to prevent the connection damage. The critical offset distance is 0.7-0.8 times of the height of the lower wall judging from the critical failure surface, but the value determined by the distribution of reinforcement tensile strength is consistent with that of FHWA.

Key words: reinforced soil, retaining wall, stability analyses, limit equilibrium, tiered configuration